<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../vue.js"></script>
</head>
<body>
    <div id="app">{{msg}}</div>

    <script>
        var vm = new Vue({
            el:'#app',
            data:{msg:'张三'},
            beforeMount () {
                console.log('挂载之前')
                console.log(this.$el.innerHTML) // 通过this.$el获取el的DOM元素
            },
            mounted () {
                console.log('挂载之后')
                console.log(this.$el.innerHTML)
            }
        })
    </script>
</body>
</html>